He may be at risk of falling off the main presidential debate stage, but Sen. Rand Paul is at long last getting his colleagues to vote on his proposal to audit the Federal Reserve.

The Kentucky Republican said he tried and failed to get Sen. Harry Reid, D-Nev., to schedule a vote on the central bank legislation back when the Democrats held the majority. When asked if he would ultimately like to wind down the Federal Reserve, Paul focused on the task at hand.

"'Audit the Fed' still has an uphill climb, even in the Senate, and so we'll see how the vote goes with that. I have said repeatedly though, throughout my time in public life, that the Fed has too much power, and that its power to manipulate interest rates has been deleterious, it hasn't been good for the economy," Paul told reporters on a Monday conference call.

"I do want to have more of a marketplace and less of a Fed, but I am an incrementalist in the sense that I'm trying to get what we can possibly get through," Paul said. "It took a long time even for the concept of 'Audit the Fed' to come forward, and then it became very popular in the House, unfortunately we have the resistance of some establishment Republicans in the Senate, so it's going to be difficult."

On Monday, Paul was pressuring liberal members of the Democratic caucus, including presidential hopeful Bernard Sanders, I-Vt., to back a vote on the audit measure on Tuesday. The bill would remove limits on the oversight of the Fed by the Government Accountability Office, effectively subjecting the bank to a more comprehensive audit, including sensitive matters related to monetary policy.

"We've had a lot of Democrats who claim that they're concerned about big banks ... and a revolving door between Wall Street and the big banks and the Federal Reserve," Paul said, also citing Sen. Elizabeth Warren, D-Mass., among "loud voices."

The vote itself to limit debate on taking up the "Audit the Fed" measure, requiring 60 votes, is set for 2:30 p.m. EST Tuesday, hours before the joint session of Congress for the State of the Union address.

As for this week's Fox Business debate in South Carolina where Paul could be forced to participate in the "undercard debate," Paul cited recent polling putting him in the top six as justification for being on the prime-time stage.

"I don't think there's any way, anybody in clear conscience could try to exclude us from being on the main stage, so we expect to be included on the main stage on the strength of the last polling," Paul said. "I think there's a lot of evidence that would be difficult to overcome to try to exclude us."

Paul has also written to his Senate colleagues ahead of the vote in a bid to preempt critics. In the letter, provided first to Roll Call, he calls the argument that the bill's transparency mandates could cause issues for the markets, "the most bizarre."

"Audit the Fed does not open a real-time window into the Fed or order the public release of any confidential information. Like the partial audit ordered by Dodd-Frank, the first audit is due in one year, and GAO will have the ability to conduct other audits moving forward. As any Member who has worked with GAO knows, that is a slow and thorough process, with even the simplest reports taking months to complete," Paul wrote. "Furthermore, even the most casual observer understands that it is the Fed's actions themselves that move markets, as has been evident over the last few weeks. To say that a retrospective non-partisan review is going to somehow disrupt the markets that already know what actions the Fed has taken is nothing short of baseless fear-mongering."